This Week's Guests:

• Sam MeachamExplorer and National Geographic Waitt grantee Sam Meacham regularly goes underground to explore some of the longest underwater cave systems in the world. Meacham joins Boyd in the studio to talk about his work far beneath the jungles of the Yucatán Peninsula.See Slideshow

• Henry RollinsAre some people just born to rage? That is the question ex-punk rocker-turned commentator Henry Rollins is trying to answer on the new National Geographic Television Explorer episode “Born to Rage,” airing Tuesday, Dec. 14 at 10 p.m. Rollins joins Boyd to talk about his search for the warrior gene that shows up in 30 percent of the male population and can be a factor in violent behavior.See Preview

• David QuammenBats, while creepy, are crucial to controlling insect populations and are important pollinators for commercial agriculture. Now, a previously unknown disease is causing massive die-offs in the bat population. Author David Quammen joins Boyd to talk about his article “Bat Crash” in the December National Geographic magazine.Read More

• Laly LichtenfeldGood fences make good neighbors. National Geographic Big Cats Initiative grantee Dr. Laly Lichtenfeld has taken this saying to heart. Lichtenfeld is working to save lions in Tanzania by helping people protect their cattle with better fences. She joins Boyd to talk about her work.Read More

• David Braun-NG NewsJoin National Geographic's daily online news editor David Braun as he shares some of the week’s hottest stories. Braun explains why bats fly better with their eyes closed.Read More

• Tom CampionThe Arctic National Wildlife Refuge, which encompasses nearly 20 million acres of wilderness along Alaska’s North Slope, is 50 years old this week. Tom Campion chairs the board of the Alaska Wilderness League and is fighting to prevent drilling in the refuge. Campion joins Boyd in the studio to talk about why it’s vital to protect this region.Read More

• Ed WoodsThe Billie Swamp Safari offers visitors face-to-face encounters with ostriches, American bison, wild alligators, venomous snakes, and many other swamp animals. As the park’s director, Ed Woods and his team of swamp men are responsible for working with these animals. It can be a tricky job, and much of it is captured in the second season of “Swamp Men,” airing Dec. 13 at 7 p.m. on the National Geographic Wild channel. Woods joins Boyd to talk about the show.See Preview

• Ken CroswellThe Milky Way, home to planet Earth, is something to be proud of, says Ken Croswell, author of the December National Geographic magazine article “ Star Struck.” Croswell joins Boyd to talk about our sun, the black hole at the middle of our galaxy and why we live in a pretty special place.Read the Article

• Colin RichColin Rich is a cinematographer looking for a new perspective. That’s why he regularly launches his own weather balloons with payloads of point and shoot cameras to capture remarkable images of the Earth from space. Rich joins Boyd to talk about his balloons and the adventures of recovering them after each flight.See Video